Synthesis and structural characterization of the new quadridentate N3S-compound di-2-pyridyl ketone thiosemicarbazone and its binuclear copper(II) complexes

Abstract

The new quadridentate, N₃S-compound di-2-pyridyl ketone thiosemicarbazone (HL) has been characterized by spectroscopic techniques and single-crystal X-ray analysis. The thiosemicarbazone moiety adopts a configuration with N(1)cis to N(3). The chelating behaviour of the deprotonated compound (L) has been investigated in two dinuclear copper(II) complexes, [(CuLCl)₂]·2dmf 1(dmf = dimethylformamide) and [{CuL(CN)}₂]·2MeOH 2. The crystal structures of 1 and 2 were determined. The co-ordination geometry about the copper(II) in both compounds is distorted square pyramidal with one pyridine nitrogen atom, the sulfur, the imino nitrogen, and a chloro or cyano group in the basal plane; a pyridine nitrogen atom of an adjacent moiety occupies the apical position, serving as a bridge to form a centrosymmetric dimeric structure.